Starting a goat farm project

Q: I am to start a goat farm project in partnership that requires 57 lakh rupees and 120 sqmt piece of land. The land is of my grandfathers. 53 lakh rupees the bank is giving a loan and the remaining 4 lakh are devided in 4 partners as 2.5 lakh myself, and 50000 each by 3 partners. Net Profit will start from 3rd year after deducting all expenses. If the profit  is 100 rupee then my questions are:

1) How much (%) share of profit will be between partners.

2) How much share will be the land owners as the market value of the land is 3 lakh?

3) Land owner that is my grand father is expired so can that share be devided among 16 members of  his family?

Waqf

Q: Could you please explain the defenition of waqf? What are the rights of the waaqif?

Fulfilling the promises one made to Allah Ta'ala

Q: If a person makes a general promise to Allah like for example Allah I promise that I will pray all 99 names every night. Or I promise to read certain amount of durood every night. Or I promise to study this amount, He says these outloud. Is he sinful for not doing these. Are they permanent or can a person speak to Allah in his duaa and take it back? And what if he forgot a certain promise he might have made, will he be accountable for that?